Sodium react with proteins

Sodium nitrite can react with proteins in the stomach or during cooking, especially in high heat (such as frying bacon), to form carcinogenic N-nitrosamines. To prevent this, ascorbic acid or erythor-bic acid is commonly added to cured meats. 

Oxidizing bleaches kill microbes by reacting with cell membranes and cell proteins. The most widely used is sodium hypochlorite for household and hospital uses, and calcium hypochlorite for drinking water and swimming pool disinfecting. 

Dissolve a protein or macromolecule containing primary amines at a concentration of 10 mg/ml in 50 mM sodium phosphate, 0.15 M NaCl, pH 7.2. Other non-amine-containing buffers such as borate, HEPES, and bicarbonate also may be used in this reaction. Avoid sulfhydryl-containing components in the reaction mixture as these will react with the pyridyl disulfide end of SPDP. The effective pH for the NHS ester modification reaction is in the range of 7-9, but hydrolysis will increase at the higher end of this range. 

Dissolve the purified SPDP-modified dendrimer of step 5 in 50 mM sodium phosphate, 0.15M NaCl, pH 7.5, or in DMSO at a concentration of at least lOmg/ml. Add a 10-20 X molar excess of an amine-reactive fluorescent molecule (i.e., NHS-rhodamine or a hydrophilic NHS-Cy5 derivative see section on fluorescent probes). React with mixing for 1 hour at room temperature. Purify the fluorescently labeled SPDP-modified dendrimer using gel filtration or ultrafiltration. Follow the method of either step 7 or 8 to conjugate the dendrimer to another protein or molecule. 

Figure 14.21 Aldehyde-particles can be reacted with amine-containing proteins or other molecules to form intermediate Schiff bases, which can be stabilized by reduction with sodium cyanoborohydride.

Dissolve an antibody or protein to be modified at a concentration of l-10mg/ml in 0.1 M sodium phosphate, 0.15M NaCl, pH 1.2-1.5. Lower concentrations of protein may result in decreased reaction yields and require increased quantities of reagent to obtain acceptable levels of biotinylation. Avoid amine-containing buffers or components, such as Tris or imidazole, which will react with the NHS ester and interfere with the biotinylation process. 

Treatment for nonketotic hyperglycinemia is less effective than that available for other aminoacidurias. There is no specific therapy. Exchange transfusion and dialysis usually do not alter the progressive neurological deterioration. Sodium benzoate has been administered in the hope that glycine would react with it to form hippuric acid, but this approach is not helpful. It may be that a combination of benzoate and carnitine therapy is more effective [28]. Similarly, the restriction of dietary protein... 

Condensed phosphates containing three- atoms of phosphorus are tripolyphosphates, the most important of which is sodium tripolyphosphate (.STPP). This compound reacts with the protein in meat, fish, and poultry to prevent denaturing or loss of fluids. This properly is sometimes called "moisture binding. STPP also solubilizes protein, which aids in binding diced cured meat, fish, and poultry. It also emulsifies fat to prevent separation. 

SALTING OUT. Reduction in the water solubility of an orgamc solid or liquid by adding a salt (usually sodium chloride) to an aqueous solution of the substance. Ions of the dissolved salt attract and hold water molecules, tli us making them less free to react with the solute. The result of this is to decrease ihe solubility of the solute molecules with consequent separation or precipitation. Colloidal suspensions of proteins, soaps, and similar substances are precipitated in tins way. 

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